1. Field of the Invention
The present invention is generally directed to memory, and more particularly to programming the non-volatile section of a non-volatile Static Random Access Memory (SRAM) from the bit lines of the volatile section.
2. The Relevant Technology
Semiconductor memory devices are widely used in the computer and electronics industries as a means for retaining digital information. A typical semiconductor memory device is comprised of a large number of memory elements, known as memory cells, that are each capable of storing a single digital bit. The memory cells are arranged into a plurality of separately addressable memory locations, each being capable of storing a predetermined number of digital data bits. All of the memory cells in the device are generally located upon a single semiconductor chip which is contacted and packaged for easy insertion into a computer system.
A particular semiconductor memory device has a non-volatile portion and a volatile portion. The non-volatile portion typically has a dual memory stack configuration, with each stack having a number of transistors, including at least one SONOS transistor. The volatile portion is typically an SRAM that is coupled to the non-volatile portion for the transmission of data there between. The non-volatile portion is typically programmed using the data from the volatile portion. Since silicon area is at such a premium in semiconductor memory and the desire is always to decrease the space and increase the speed, functionality and efficiency, alternate ways of programming and erasing are desirable.
It would be advantageous to provide a method and apparatus for programming the non-volatile section of the semiconductor memory from the bit lines associated with the volatile portion without utilizing additional silicon overhead associated with a voltage supply node to the non-volatile section.